... protection* LED indication and audible alarm function* Intelligent battery management * Cold start function * Automatic battery charging in UPS off mode( Option)* with ... voltage, under-voltage, over-load, short circuit, battery low limit) 11.Build-in battery: 12V DC 4.0AH or 7.0AH 12 ... is off, it sends slow alarm sound; When the battery is used up, it sends fast alarm sound. REMARKS: High efficiency , ...